Understanding Resolution & Digital CamerasAnn WareBald Knob High School*
ResolutionUnderstanding digital cameras requires that we know how resolution works.
Resolution is determined by how many pixels (picture elements) or dpi (dots per inch) are available. The image you see is simply a grid of small squares or circles filled in with color. The more squares or circlesthe sharper the image.*
Measuring Resolution*Resolution is measured by the number of horizontal pixels times the number of vertical pixelsExample: 3072 x 2304
MegapixelsThe quality of a picture is measured by its resolutionhow many pixels it has; the current measurement is megapixels A megapixel is a grid containing one million pixels (one million squares of color)technically, that is an image with a resolution of 1024x1024 pixels*
ResolutionWith computer graphics, there are three different resolutions to consider:the images resolution (pixels)the monitors resolution (pixels)the printers resolution (dpi)
Image ResolutionThe images resolution is measured in pixels. Most cameras allow you to change the resolution before you take the picture. The higher the resolution the clearer the image the bigger the file size.*
Monitor ResolutionMonitor resolution is measured in horizontal and vertical pixelsExample: 1024x768 If an image is taken at 1280x960, but your monitor can only display 1024x768 thats as good as it gets!*
Printer ResolutionPrinter resolution is measured in dpidots per inch. The quality of the printed image is going to be determined by both the resolution of the image AND the resolution of the printer.
Point and Shoot CamerasMost digital cameras designed for the consumer (vs. professional) are point and shoot camerasThey fall into three categories: subcompact, compact and super zoomThe camera lenses are built-in (not removable)Basic features typically include auto focus, auto exposure and built-in flashNot appropriate for action photography because of lag time*
SLR Cameras (Single Lens Reflex)With an SLR camera, you see exactly what the lens sees You can change the lens on a digital SLRYou choose the lens based on the type of photography; example: portrait photography vs. sporting events vs. landscape photography, etc.SLRs produce higher-quality photos than point and shoot camerasAn SLR has a near-zero lag time, and is ideal for action photography
Other points to considerWhen purchasing a camera, you should also research the following specifications:Storage CapacityTransferring ImagesPower SourceLCD vs. Optical View FinderZoomImage StabilizationThe Exposure Triangle (Aperture, ISO, Shutter Speed)
Storage DevicesMemory CardInternal Memory (RAM) The number of pictures you can take before sending them to your computer is determined by two things:The resolution of the imageThe type of storage
Transferring ImagesCard reader USB cableBluetooth*
Power SourceRegular BatteriesRechargeable batteriesAlkalineNickel-metal hydride (NiMH)Lithium-ion (Li-Ion)AC*
LCDs vs ViewFinderLCDProsShows you the exact image that will be recordedEasy to view delete images, etc.Displays menuLCDConsDrains batteryuses life of batteryDifficult to see in bright light*View FinderProsUses less batteryEasier to see images in bright light View FinderConsShows close approximation of the final imagenot the real thingDifficult for some people to see
ZoomOptical zoom actually enlarges the imagemeasured in Xexample: 8Xincreases an image 8 timesDigital zoom takes a portion of an image an enlarges it electronically; the image loses resolution when the camera enlarges it; also measured in XMacro zoom allows you to take close-up pictures of objects that are small and enlarge them so they appear larger.*
Image StabilizationA feature in digital cameras that reduces the vibrations that can occur when taking a picture.Vibrations commonly occur when shooting at slow shutter speeds, with longer lenses or with digital zoom.Also called anti-shake*
The Exposure TriangleExposure is the total amount of light you let into your camera. Too much light results in an over-exposed image where there are areas of bright white orblow-outs. These areas contain no detail or color. Too little light and an under-exposed image leaves parts of your imagetoo dark to make out details.The three components to exposure are ISO, shutter speed and aperture*
The Exposure TriangleISOthe measurement of how sensitive the image sensor in the camera is to light.Measured in numbers 100, 200, 400, 800, etc.Use a lower number when smooth crisp images are need and you have plenty of light.Higher numbers are used when light is limited, you do not want to use a flash, or the subject is moving; may result in grainy images*
The Exposure TriangleShutter Speedthe amount of time the shutter is openwhich determines how much light is captured in the recording processMeasured in seconds: super fast 1/2000 second to 30 secondsThe slower the speed, the longer light can enter the camera. Appropriate for shooting pictures in darker situations; also great for freezing action and movement*
The Exposure TriangleAperturethe camera feature that regulates the amount of light that passes through the lens by controlling the size of the opening in the lensDescribed as the f/stop (a stop is a change in setting)The smaller the number the wider the lens will open*
The arrow is a link to the last slide, which is a picture of a lily. A portion of the center of the lily is enlarged in the top right corner to show the pixels.*Question: What happens if the image resolution is higher than the monitor resolution?
Answer: You will not be able to view the image at its best quality
Question: What if the printer resolution is lower than the image resolution?
Answer: Your printed image wont be the optimum quality. To get the optimum quality you will have to have it printed professionally.**http://www.digital-slr-guide.com/what-is-a-digital-slr.html**http://www.mamma-razzi.com/2011/02/exposure-triangle/*